Bifunctional aminophosphanes (Et 2N) 2P(CH 2) nP(NEt 2) 2 and (Et 2N) 2PP(NEt 2) 2 as ligands in metal(O) carbonyl complexes of Cr, Mo and W

Abstract

Depending on the value of n, bifunctional aminophosphanes (Et 2N) 2P(CH 2) n-P(NEt 2) 2 (LL) have been shown to form either mononuclear complexes (CO) 4M cis-(LL) (M = Cr, n = 1–4; M = Mo, W, n = 4) or binuclear compounds [(CO) 4M(LL)] 2 (M = Cr, n = 5–10) with ligand bridges in trans-positions. By suitable choice of reaction conditions, (CO) 5M(LL)M(CO) 5 (M = Cr, Mo, W, n = 4) containing only one ligand bridge can also be obtained. In the former compounds complete or partial substitution of amino groups by HBr was carried out, to give (CO) 4M cis-[Br 2P(CH 2) 4PBr 2] (M = Cr, Mo), and (CO) 4W cis-[Et 2N(Br)P(CH 2) 4P(Br)NEt 2], respectively. By the same method (CO) 5CrBr 2PPBr 2Cr(CO) 5, in which P 2Br 4 is stabilized by complex formation, was obtained from (CO) 5Cr(Et 2N) 2PP(NEt 2) 2Cr(CO) 5. The NMR, IR and mass spectra of the complexes are discussed.